Portable treadle mechanism for sewing machines



United States Patent [72] Inventor Karl D. Schweers [56] References Cited Spring Valley, New York UNITED STATES PATENTS [2 1 pp N9 817,083 227,515 5/1880 French 74/138 f ted 355 333 699,171 5/1902 Holtz 74/138 a en [73] Assignee The Singer Company FOREIGN PATENTS New York New York 54,616 Germanym 1. 74/138 a corporation of New Jersey 597 191 1 Great Br1ta1n.... 74/141 609,156 9/1960 Italy l12/217.4

Primary Examiner-H. Hampton Hunter Attorneys-Marshall J. Breen, Chester A. Williams, Jr. and

Robert E. Smith [54] PORTABLE TREADLE MECHANISM FOR SEWING MACHINES 10 Claims, 4 Drawing Figs ABSTRACTt A treadle mechanism is disclosed for a sewmg machine having a one-way clutch connected to the mam shaft.

This mechanism includes a treadle which is effective to trans- 3, /217 mit foot power when it is simply placed on a floor i.e., without [51] Int. Cl D05b 69/00 a cumbersome support frame, A flexible belt and return spring Field Search 1 0, arrangement is disclosed having a connection at a single point 218, 217.1, 12, .3. v4: 74/138. 141, 142, to the treadle to facilitate rapid folding into compact form for 185/37, 38 storage or transport of the treadle mechanism.

Pa tented Dec. 1,1970 'v 3,543,707

INVENTOR. Karl D. Schweers WITNESS:

,. K eye/04 Juivfy- Wcwom v I AT TOR PORTABLE TREADLE MECHANISM FOR SEWING MACHINES BACKGROUND OF THE INVENTION DESCRIPTION OF THE PRIOR ART A wide variety of treadle mechanisms is known in the prior art including those in which a spring-returned flexible belt drives a sewing machine by way of a one-way clutch connected to the main drive shaft. In none of the known constructions, however, is the treadle mechanism conveniently portable because each is permanently associated with a bulky support frame and provided with drive connections which would require the use of tools and considerable time to dismantle for storage or transportation.

SUMMARY OF THE INVENTION It is an object of this invention to provide a treadle drive for a sewing machine which is conveniently portable in the sense that it may be detached from the sewing machine and folded into a compact arrangement for storage or transportation quickly and without the use of tools.

It has long been common to organize a sewing machine so that it is portable; this involves the provision of a compact base or machine-supporting structure, and usually some sort of facility for carrying the machine whereby use of the machine is not limited to any predetermined stand or cabinet. Insofar as portability is concerned, it is as important that the sewing machine may be operated conveniently in any one of a variety of locations as it is that the machine may be transported easily. With electric motor driven sewing machines, and with hand powered machines in which the crank or hand power attachment remains an integral part of the machine, no particular problem presents itself in providing portability. Where a dependable supply of electricity is not available, however, foot power is a particularly desirable form of sewing machine drive because it frees both hands of an operator for manipulation of work.

Until this invention, however, the foot power drives or treadle mechanisms which have been known have not been conveniently portable so that where foot power was necessary, the advantages of a portable sewing machine could not be fully realized because of the availability of only cumbersome nonportable treadle drives.

The objects of this invention are attained by the provision of a treadle which is operable without the necessity of a supporting frame or stand, and which operates by being placed directly on the floor to act as a foot operated lever in reciprocating a flexible drive belt. To further facilitate storage and transport of the treadle mechanism of this invention, the flexible drive belt and a return spring therefor, are each attached to the treadle at closely adjacent points, preferably by a common ferrule. In this way the belt in storage may simply be wrapped about or folded alongside the treadle. The treadle mechanism of this invention is, therefore, conveniently portable to a degree far surpassing any previously known and is thus highly advantageous in making available the benefits of portability for sewing machines where foot power must be used.

DESCRIPTION OF THE DRAWING The accompanying drawing illustrates a preferred embodiment of this invention in which:

FIG. 1 is a perspective view of a portable sewing machine to which the treadle drive of this invention has been applied,

FIG. 2. represents an enlarged vertical cross-sectional view of the one-way clutch device connected to the main drive shaft of a sewing machine and of the treadle drive of this invention,

FIG. 3 is a cross section through the one-way clutch device taken substantially along line 3-3 of FIG. 2, and

FIG. 4 is a perspective view of the treadle mechanism detached from the sewing machine and folded for storage.

Referring to the drawing, a portable sewing machine ii is illustrated in FIG. 1. The sewing machine is fitted onto a small base 12 and is adapted to be placed on any desired support such as a-table 13 which is illustrated in phantom lines to indicate that it need not be of any predetermined design.

The treadle mechanism of this invention requires that a oneway clutch device be associated with the sewing machine. In the accompanying drawing such a one-way clutch device is indicated generally at 14 and is illustrated in detail in FIGS. 2 and 3. Although other locations for the one-way clutch and other means of connection of the one-way clutch with the driven parts of the sewing machine may be used, the accorn panying drawings illustrate an arrangement in which the one way clutch 14 is carried on the sewing machine arm shaft 15 journaled in bushings such as bushing 16 in the sewing machine frame 17.

An arm shaft extension 18 is formed with an axial bore 19 embracing the arm shaft. One or more set screws 20 secure the arm shaft extension for rotation with the arm shaft. The arm shaft extension is formed exteriorly with a large diameter portion 21 on which is journaled the hub 22 of a handwheel 23. An annular flange 24 on the arm shaft extension limits the position of the handwheel axially. The arm shaft extension is formed with a small diameter portion 25 on which is journaled a belt pulley 26 formed with an outer flange 27 and with an inner flange 28. The inner flange 2b is formed with an axial extension 29 which telescopes into an annular cavity 30 formed in the handwheel hub 22. The cavity 30 provides an outer clutch race and the pulley extension 29 is formed with a pair of diametrically spaced tapered recesses 31-31 providing inner clutch races in which cylindrical clutch rollers 32-32 are disposed. Although'fthe rollers 32-32 may be arranged freely within the tapered recesses 31, it has been found preferable to form each roller with a central necked portion 33, on which is wrapped one extremity of a spring wire 3d which is secured at the other extremity in a reception socket 35 in the pulley extension 29. It is the function of the spring wires to lightly bias the rollers outwardly so as to prevent the clutch rollers from sticking. Because of the tapered recesses 31, the clutch rollers will lock the pulley 26 for rotation with the handwheel when the pulley 26 is turned in a counterclockwise direction as viewed in FIG. 3 and the pulley 26 will be declutched so as to turn freely relatively to the handwheel when the pulley is turned in a clockwise direction as viewed in FIG. 3.

For constraining the belt pulley 26 on the arm shaft extension 18, a knob 36 is provided at the free extremity of the arm shaft extension. The knob is fixed to one end of a stud 37 threaded axially into the arm shaft extension. The knob 36 and threaded stud 37 serve also as a clamp for selectively securing the handwheel to the arm shaft. For this purpose, the arm shaft extension 18 is formed diametrically with a slot 38 in which a locking bar 39 is arranged. The slot is disposed so that the locking bar can abut the handwheel hub 22, and when the threaded stud 37 abuts the locking bar it clamps the handwheel hub tightly against the flange 24 to lock the handwheel relatively to the arm shaft.

As illustrated in FIG. 1, the treadle drive of this invention includes a treadle indicated generally at 40 preferably formed of rigid material such as wood, metal or plastic and including a pair of arms 41 and 42 diverging at an obtuse angle from a juncture 43 which juncture defines a fulcrum for the treadle 40 relatively to any substantially flat floor on which the treadle may be placed. A layer of cushion material M such as rubber or the like may be applied to the juncture 43 as by an adhesive in order to minimize slippage of the treadle.

The treadle arm 41 may be formed in one piece or, as illustrated in FIGS. 1 and 4, may include a separate outer portion 45 connected to thearm 41 by a hinge 46. The hinge axis is preferably arranged beneath the treadle so that the abutting ends 47 and 48 of the arm 41 and of the outer portion 45 will lock the treadle section in substantially coplanar relation as viewed in FIG. 1 where a force is applied downwardly'on the treadle. When not in use, the treadle sections may be folded upon each other for compactness in storage as illustrated in FIG. 4.

Near the free end the outer portion 45 of the treadle is formed with a clearance hole 49 upwardly through which extends the reduced diameter neck portion 50 of a ferrule Sl having a flange 52 larger than the hole 49. The ferrule is formed with a bore 53 through which extends one extremity 54 of a flexible belt 55 to which a retaining element such as a nut 56 is secured to prevent the belt extremity from being pulled out of the bore.

The neck portion f) of the ferrule is formed externally with a spiral groove 57 which accommodates several convolutions of a coil spring 58 to secure the spring to the ferrule 5i. A plastic tape 59 may be applied over the spring convolutions on the spiral groove 57 to insure that the spring will remain thereon, however, it is usually sufficient if the spring coils are made slightly smaller in diameter than thatof the spiral groove in the ferrule. Preferably the coil spring is of a diameter greater than the hole 49 so that the ferrule 51 will be loose in the hole 49 but yet constrained on the treadle extremity.

At the upper extremity the coil spring is engaged for several convolutions in an external spiral groove 60 formed on a second ferrule 61. Similarly a plastic tape 62 may be wound about the spring convolutions on the spiral groove 60 to lock thecoil spring to the ferrule 61. The ferrule 61 is formed with a clearance hole 63 through which that extremity 54 of the belt 55 which is connected to the lower ferrule 51 may pass freely. The upper ferrule '61 is also formed with a second hole 64; through which extends the opposite extremity 65 of the belt 55. A retaining clip 66 is applied to the belt extremity 65 beyond the ferrule 61 to prevent withdrawal of the belt out of the ferrule 61'.

To use the treadle device of this invention it is only necessary to wind two turns of the flexible belt 55 about the pulley 26 of the one way clutch l4 and to place the treadle 41 on the floor. The sewing machine can then be driven simply by alternately applying downward pressure to the treadle arm 41 and releasing such downward pressure. Upon application of downward pressure to the treadle as by the operators foot, the belt extremity 54 will be drawn downwardly and the coil spring 58 will be distended to permit the opposite extremity 65 of the belt to move upwardly. The pulley 26 of the one-way clutch 14 will thus be driven in one direction by the belt movement during depression of the treadle. Preferably the belt should be wrapped on the pulley 26 in such a direction as to cause the clutch rollers 32-32 to lock during treadle depression thus making treadle depression the driving stroke of sewing machine operation. When the downward force on the treadle is discontinued, the energy stored in the coil spring 58 will return the treadle and cause the belt to shift in the opposite direction. The pulley 26 will be turned in the opposite direction during such return movement but the clutch rollers will not transmit this movement to the sewing machine arm shaft.

When the treadle device is not in use, the belt 55 is unwound from the pulley 26, the outer portion 45 of the treadle is folded onto the treadle arm 4i, and the belt 55 may be wrapped around the treadle to provide a compact arrangement for storage. The treadle device of this invention may thus be readied for use or for storage quickly and without use of tools.

lclaim:

l. A portable treadle drive for a sewing machine having a main drive shaft, a one-way clutch device, and means for operably interconnecting said one-way clutch device to said main drive shaft, said treadle drive comprising a flexible belt adapted to be placed in driving relation to said one-way clutch device, a treadle member having means thereon adapted to define a fulcrum for angular movement of said treadle member when placed on a substantially flat surface, means for securing one extremity of said flexible belt to saidtreadle member at a-position remote from said fulcrum means, extensible spring means, means for securing said extensible spring means to the opposite extremity of said flexible belt, and means for anchoring said extensible spring means to said trea dle member closely adjacent to the position on said treadle member of said means for securing said one extremity of said flexible belt thereto, said treadle member being otherwise free of connection to said sewing machine whereby said treadle drive is adapted to be readily separable from said sewing machine.

2. A treadle drive for a sewing machine as set forth in claim l in which the extensible spring means comprises a coil spring of which the coils embrace said one extremity of said flexible belt which is attached by said securing means to said treadle.

3. A treadle drive for a sewing machine as set forth in claim 2 in which the means for receiving one extremity of said fiexible belt to said treadle member and the means for anchoring said extensible spring means to said treadle member comprise a single ferrule formed externally with groove means accommodating convolutions of said coil spring, and formed internally thereof with said means securing one extremity of said. flexible belt thereto, and means for securing said ferrule to said treadle member.

4. A treadle drive for a sewing machine as set forth in claim 3 in which the means for securing the coil spring to the opposite extremity of said flexible belt includes a ferrule formed externally with groove means accommodating convolutions of said coil spring, and formed internally thereof with both means for securing the opposite extremity of said flexible belt thereto, and with a clearance aperture for the one extremity of said flexible belt secured to said treadle member.

5. A treadle drive for a sewing machine as set forth in claim 1 in which said treadle member is formed with a pair of arms diverging at an obtuse angle relatively to each other from a juncture, said obtuse angle juncture providing said means defining a fulcrum for angular movement of said treadle member relatively to any substantially flat floor, said means securing one extremity of said flexible belt to said treadle member and said means for anchoring said extensible spring means to said treadle member being attached to said treadle member near the extremity of the same one of said pair of treadle arms.

6. A treadle drive for a sewing machine as set forth in claim 5 in which a layer of cushioning material is applied to the treadle member at a juncture of said pair of arms.

7. A treadle drive for a sewing machine as set forth in claim 5 in which that one of said treadle member arms to which said flexible belt securing means is attached comprises plural sections joined by hinge means including abutment stops locking said plural sections in substantially coplanar relation whenever a force is applied by said treadle member to extend said spring means.

8. In combination a sewing machine having a main drive shaft, a one-way clutch device including an oscillatable belt pulley, a wheel, and means effective to establish driving interlock therebetween in only one direction of oscillation of said belt pulley, means for establishing a driving connection between said wheel of said clutch device and said main drive shaft, and a portable treadle device comprising a flexible belt engageable with said belt pulley, a treadle member having means thereon adapted to define a fulcrum for angular movement of said treadle member when placed on a substantially flat surface, means for securing one extremity of said flexible belt to said treadle member at a position remote from said fulcrurn means, extensible spring means, means for securing said extensible spring means to the opposite extremity of said flexible belt, and means for anchoring said extensible spring means to said treadle member closely adjacent to the position on said treadle member of said means for securing said one extremity of said flexible belt thereto, said treadle member being otherwise free of connection to said sewing machine whereby said treadle drive is adapted to be readily separable from said sewing machine.

9. The combination as set forth in claim 8 in which said belt pulley and said wheel of said one-way clutch are journaled 10. A combination as set forth in claim 9 in which said wheel comprises a handwheel for manually operating said sewing machine. 

